There is a lot of debate on the right way to introduce new chickens into your flock. We have tried a few different methods over the years. Here is what we have found to work the best. We are lucky enough to have a few spare coops around the property. We always start with complete confinment for a two week period, this allows us to monitor for illness. The next step is allowing them into a closed safety run, where they can see and chat with the other birds, but no fights can commence. This stage takes a week or two normally, Before they are ready to be let free to range with the flock. They continue to sleep in separate coops for another few weeks. Then they are added into the large flock housing at night. When we are dealing with babies the same steps apply just at a slower rate of time. We have found this method to work nicely for us. If you do not have extra housing available, you can always separate the coop into sections. We have even used children's playpens to segregate chicks of different ages. Placing pens close to each other for safe interactions.